Problem
It is not possible to access Exalate because the Extensions section is missing in the Azure DevOps Organization settings menu.
Cause
This is caused by a bug in Azure DevOps: Reported bug
The bug has been confirmed to be resolved. Please raise a ticket on our support portal in case it happens again.
Solution
Use this link to access Exalate:
https://dev.azure.com/{your_organization_name}/_settings/idalko-tools.exalate.adnode{your_organization_name} is the name of your Azure DevOps organization.